Our library has an art lesson weekly so we do that every week! We sign up for t-ball, that is a good 8 weeks worth of Phy-ed! 
We go camping and theylearn about the lake, animals, woods and I take them to historic parts of the park and explain how the log cabin was built and the famous Souix uprising in our area (and the one lady who was spared bc they gave the braves some water!) We go to the fairs and see animals and projects. Some years we have visited the zoo. I take them to art stores to see and explain tasteful art. WE have went to Walnut grove (45 minutes away) and see the Laura Ingals Wilder muesum. I do want to throw some math in once or twice a week to keep up with that on my children. So Fun is the key but learning mixed in when they don't know it! I plan to do a little reading with her through June and July. During that time, we have much going on - VBS, an out-of-state trip, on which I am hoping to stop and see my son, daughter-in-law, and grandson , picnics, a week of camping, fishing, etc. When we aren't doing these things, we will spend time outside. My dd has her own little garden tools, so I want to let her plant a little garden of her own. We also have a new puppy which will occupy some time. We will begin LHFHG full swing in early August. That is usually when I began the year when my older kids were homeschooling. It's good to give a break from the routine of school. Then they can look forward to starting a new year. You can still keep some structure in your days of summer activity 
Have fun We pretty much school year- round and take time off at different times of the year. Holidays and sometime in the spring. Whatever works for our schedules and vacations! Working in the garde: I give the kids a part of the garden where they can plant their own vegetables or flowers. Someone gave us a few recorders and I already had a "teach yourself recorder" book, so we plan on learning recorder this summer also. I am also planning on looking into our local 4-H to see what is available for the summer.